Simulating Redox Potentials of Biomolecules: the Case of Cryptochrome 1 from Arabidopsis thaliana
2019-02-11T17:42:03Z (GMT) by
Redox reactions play a key role in various biological processes, including photosynthesis and respiration. Quantitative and predictive computational characterization of redox events is therefore highly desirable for enriching our knowledge on mechanistic features of biological redox-active macromolecules. Here, we present the results of computational studies of the redox potential of ﬂavin adenine dinucleotide (FAD) in cryptochrome 1 from <i>Arabidopsis thaliana</i> (Cry1At). The special attention is paid to fundamental aspects of the theoretical description such as the eﬀects of environment polarization and of the long-range electrostatic interactions on the computed energetic parameters. Environment (protein and the solvent) polarization is shown to be crucial for accurate estimates of the redox potential: hybrid quantum-classical results with and without account for environment polarization diﬀer by 1.4 V. Long-range electrostatic interactions are shown to contribute signiﬁcantly to the computed redox potential value even at the distances far beyond the protein outer surface. The theoretical estimate (0.07 V) of the midpoint reduction potential of FAD in Cry1At is reported for the ﬁrst time and is in good agreement with available experimental data.